1. Field of Invention
Abrasive media for use in finishing processes and in finishing machines of the vibratory or tumbling-barrel types for the finishing, e.g., deburring, burnishing, edge-breaking, and polishing of parts or workpieces therein.
2. Prior Art
Numerous types of finishing media have been proposed over the years for finishing processes and for use in finishing machines of the type here concerned. Such finishing media generally comprise loose aggregate integral units, generally referred to as finishing "chips". The earliest finishing material was loose rock aggregate, but advances in the art have provided numerous types of finishing media and chips wherein various types of abrasive grains are imbedded in a variety of binders, among the most recent of which is a ceramic type of binder. Other types of binders or cores, more properly referred to as a "matrix", have included soft metals, ice, plastics of various types, and waxes, with varying degrees of success. The most popular finishing media at present have a resin-bonded or ceramic matrix containing abrasive grains dispersed therein. Such ceramic abrasive media have traditionally been provided in pre-formed shapes, wherein the ceramic-abrasive mixture is integrally bonded by the procedure employed. After providing the traditional pre-formed shapes, they are usually dried at relatively high temperatures, approximately 700.degree. F., for a period of up to 45 hours, and then fired at temperatures above the sintering temperature, such as 1900.degree. to 2700.degree. F., for additional periods of up to 20 hours. Although adequate in practice, the cost of fuel, e.g., gas or electricity, for providing the necessary high temperatures in such processing has become prohibitively expensive. It is apparent that improved abrasive media which are satisfactory for the intended purposes of employment in finishing processes and finishing apparatus, which perform as well as or better than existing ceramic media in terms of wear rate or depreciation, and which obviate the necessity of the employment of such high temperatures and the attendant high fuel consumption, would be highly desirable.